Apparatus for determining inclination of well bores



. 1, 1942. E. M. IRWIN r-:rAL

APPARATUS FOR DETERMINING INCLINATION OF WELL l'BORES 5 Sheets-Sheet 1 Filed Sept. 7, 1937 ATTORNEY.

, l E M @Wm m AL APPARATUS FOR DETERMINING INCLINATION oF WELLI'BOREE;

Dec. 1, 1942.

E. M. lRwlN x-:rAL 2,303,360

APPARATUS FOR DETERMINING INCLINATIO 'OF' WELL BORES Filed Sept.' '7, 1957 3 Sheets-Sheet 5 T G v INVENTORS ZM 511g 116 Patented Dec. 1, 1942 UNITED STATES `TT OFFICE APPARATUS FOR DETERMINNG INCLINATION 0F WELL BORES Application September 79 1937 Seriai Nrn 162,792

14 Claims.

Our invention relates to well bore measuring devices and has particular reference to a method and apparatus for determining the angle of in clination of a well bore from the true vertical.

be rebuilt or entirely replaced after a few indications have been made by the instruments.

It is therefore an object of our invention to provide an inclination detecting and measuring In the art of drilling well bores, particularly it instrument of such rugged construction as will oil well bores, it is important to ascertain from permit the instrument to withstand any of the time to time whether the hole extends in the normal vibrations or shocks encountered in the true vertical or has deviated from the vertical drilling of an oil well and of such character as and to what extent the same has deviated from to enable the instrument if desired to be dropped the vertical so that proper correction oi the 'dilil freely into the Well bore Without danger of rection of the well bore may be made. Hereto- Wrecking the instrument When ill Strikes the b015- fore it has been the practice to interrupt the tom of the bore. drilling operations from time to time for the pur- Another object of our invention is to provide pose of measuring the direction in which the hole an inclination detecting and measuring instruis being drilled and the apparatus heretofore em l ment which is relatively simple in construction ployed for determining whether the hole has ded and which may be contained within a housing viated from the vertical and to what extent have adapted to dispose its longitudinal axis parallel been complicated structures so delicate in their lwith the axis of the Well bore and in which the construction as to require extreme care in their lateral cross sectional area of the instrument is manufacture, maintenance and handling during 20 relatively small as compared with the cross secactual service. tional area of the well bore.

, Two general types of measuring or inclina Another object of our invention is to provide tion detecting instruments have been employed, an instrument of the character set forth which namely, those attached to the well drilling tools, may be attached to the boring bit or to any in the case of reciprocating tool drilling, and, 2li of the tools emplOYBd in the drilling Opelafl'llOIlS second, those types of devices which must be run and left so attached to the tools during the norinto the well from the surface of the ground each mal drilling ODGISDODS and requiring merely a time a measurement or detection is to be made. short pause in the drilling Operations for the The rst type of these devices, namely, the successful detection and measurement of any intype attached permanently to the drilling appa.- 3@ clination oi the well bore from the vertical. ratus, has failed to function satisfactorily, prianother object of our invention is to DIOVlde marily because of the delicacy with which the an instrument oi the character set forth in the various parts of the instruments must be made in preceding paragraph wherein the instrument order to produce accurate indications, such deli-1 detects and measures the angle of inclination cate construction rendering the devices unsuit-1 35 or" the Well bore without requiring the lifting able for permanent location or attachment upon or removing of th'e drilling tools out of the Well the drilling tools because the vibrations and bore. shocks encountered by the instrument during the Another object of our invention is to provide normal drilling operations is such as to rapidly QJ an instrument of the character set forth wheredestroy the instrument.

On the other hand, devices of the type insert able into the well bore from the surface oi' the ground require the shutting down of the drilling operations for an appreciable length of time, while the instrument is lowered and withdrawn. Then it must be opened and inspected in order ascertain the angularity of the hole. Also such in a plurality of angle measuring devices are employed, each of which measures a specic angle and the angle measured by each of the devices being different from that measured by the others so that the number of these devices which are actuated is representative of the angle between the longitudinal axis of the well bore and the true verticaL ther object of our invention is to provide f vice or the character set forth associated with an indicating or sounding mechanism which will transmit predetermined sound vibrations to the ground surface where these vibrations may be detected and interpreted to produce a translation of the angle of inclination of the well bore in terms of signals or records at the ground surface.

Another object of our invention is to provide an instrument of the character set forth in the preceding paragraph wherein extraneous vibrations or sounds differing from the predetermined selected sounds may be filtered out so as not to interfere with the accurate reception and translation ofthe signals transmitted by the instrument,

Another object of our invention is to provide an instrument of the character set forth wherein a plurality of angle detecting devices may be inserted into the well bore, each of the angle detecting devices including a movable member such as a ball supported upon a dish-like surface, the supporting surface of each of the devices diiering from those of the others in such manner as to allow the ball or movable member to roll from a predetermined position when the supporting surfaces are disposed at varying angles from a horizontal plane so that the number of balls or movable devices shifted from their normal positions represents the angle of inclination of the well bore to the true vertical.

Other objects of our invention and advantages thereof will be apparent from a study of the following specifications, read in connection with the accompanying drawings, wherein,

Fig. 1 is a diagrammatic elevational view of an oil well and drilling apparatus therefor, illustrating one manner of .using our inclination detecting and measuring instrument;

Fig. 2 is a detail vertical elevational view,

tecting and measuring instrument may be associated therewith;

Fig. 3 is a horizontal sectional view taken along line III-III of Fig. 2;

Fig. 4 is a detail vertical perspective sectional view taken through our detecting and measuring instrument and illustrating the manner in which a plurality of angle detecting devices may be assembled within a slender elongated housmg;

Fig. 5 is a detail horizontal sectional view through one of the angle detecting devices shown in Fig. 4, the section being taken along line V-V of Fig. 4;

Fig. 6 is a diagrammatic view illustrating the manner in-which signal receiving, ltering, amplifying, translating and recording apparatus may be associated with the ordinary oil well drilling equipment and with our inclination detecting instrument to measure and translate the inclination in accordance with our method;

Fig. 7 is a diagrammatic view illustrating the electrical connections which may be employed with one form of our instrument to translate the measurements made by our instrument into terms of predetermined sound vibrations;

Fig. 8 is a detail vertical sectional view of a modified form of detecting device which may be substituted for the detecting devices illustrated in Figs. 4 and 5;

Fig. 9 is a detail sectional view similar to Fig. 8 and illustrating a still further modified form of detecting device which may be employed;

Fig. 10 is a vertical sectional view similar to Figs. 8 and 9 and illustrating a still further modied form of detecting device which may be employed;

Fig. 11 is a horizontal sectional view taken along line XI--XI of Fig. 10;

Fig. l2 is a vertical sectional view similar to Figs. 8, 9 and 10 and illustrating a, still further modified form of detecting device which may be employed;

Fig. 13 is a diagrammatic view illustrating a modified system of electrical connections which may be employed to translate the angle measurements from the detecting devices into terms of sound vibrations;

Fig. 14 is a plan view of one of the angle detecting units which may be employed in place of the angle detecting units illustrated in Fig. 4

and illustrating the manner in which a number of these units may be so constructed that when assembled together they make electrical connections between the members to dispense with wires or other electrical conductors;

Fig. 15 is a vertical sectional view taken along line XV-XV of Fig. 14 and illustrating the manner in which electrical pin and socket connections may be employed to complete electrical circuits between several assembled detector units; and

Fig. 16 is a diagrammatic sectional view through a well bore and drilling apparatus and illustrating the manner in which our detecting instrument may be dropped or lowered into the well to make measurements without permanently attaching the instrument to the drilling apparatus.

Referring to the drawings, we have illustrated a typical well drilling installation in Fig. l, in which a well bore I is illustrated as being in the process of being drilled by means of a drill bit 2 coupled in the usual manner to a sub 3 which is in turn connected at the lower end of a drill string 4 made up in the usual manner of a plurality of sections or lengths of drill pipe extending upwardly to the ground surface 5 where the drill string is coupled in any suitable manner to a rotary table 6 driven or rotated by means of power apparatus 1. The drill string 4 is supported upon a swivel 8 which is in turn suspended upon a traveling block 8 of a block and tackle assembly of which the stationary or crown block I0 is supported at the upper end of a derrick structure II.

As is the usual practice in oil well drilling, the swivel 8 constitutes a means by which mud fluid or drilling iiuid may be circulated down through the drill string 4 and upwardly about the drill string 4 to carry away the cuttings, the mud fluid being pumped into the drill string 4 by suitable well known pumping apparatus supplying this fluid through a mud hose I2 coupled to the swivel 8.

The well bore I in Fig. 1 is illustrated as being disposed in the true verticall throughout the major portion of its length but the lower end of the well bore I is illustrated as having been deviated from the vertical at the point I3 so that, should the drilling operations 'ce continued under the conditions-"illustrated in Fig. l, the well bore will not have its longitudinal axis extending along the true vertical but would instead extend at a considerable angle to the vertical.

As will be understood by those skilled in the art. whenever the well bore deviates from the true vertical, it may be brought back to a true vertical line by employing well known bore straightening methods, tools or instruments, provided that the operator or driller knows that the bore has deviated from the vertical and particularly to what extent the bore has so deviated.

We provide an inclination detecting and measuring apparatus which will indicate to the operator the fact that the well bore has deviated from the vertical and to what extent and by employing this instrument the driller will know how to correct the improperly drilled hole and will be able to straighten the bore before serious deviation from the vertical can occur. It will i also be understood by those skilled in the art that in most instances the direction of the deviation is not material since all that is necessary is that the driller know'that there has been a deviation and he is warned to bring the hole back to a true vertical line.

We have illustrated herein an angle detecting and measuring instrument which comprises es'- sentially a housing or container I4 which may be of any suitable size or shape though we prefer that the same comprise an elongated hollow cylinder open at both its ends and fitted with closures I5 and I6, preferably threaded into the ends of the housing I4, as indicated at I'I and I8, respectively.

The interior of the housing I4 constitutes an elongated chamber into which may be assembled a plurality of angle detecting devices or units Illa, |911, |90, |9d and |96, it being understood that the number of detecting units 49a, |9b, etc.

may vary as will be hereinafter more fully described.

Each of the angle detecting units constitutes switching apparatus adapted to close or to open an electric circuit dependent upon whether or not the longitudinal axis of the housing I4 is disposed in the true vertical or is disposed at an angle to the vertical.

In the form of the device illustrated in 4, 5 and 8 through 1l, each of the units I9a, ISD, etc. comprises a disc-like member 2li having an upper surface 2| upon which a ball or other roll-` ing member 22 is adapted to be supported, the surface 2| having a depressiony 23 therein into which the ball 22 normally seats when the housing member I4 is disposed with its longitudinal axis in the true vertical. but adapted to allow the ball to be displaced from its normal position when the housing I4 is tilted away from the true vertical.

In the form of the device illustrated in Figs.

4 and 5, the surface 2| is that of a conical depressed surface extending transversely to the Disposed above the member 20 is a contact ring 24 insulated from the member 2li by a pair oi insulating rings 25 and 2B. each of which may be constructed of a suitable annular member oi insulating material having a recess 21 therein.

the recesses of the rings -Zi whenassenibled' together deiining a recess into which the contact ring 24 may seat and be held. When the ball 22 is moved from its normal or central position, the ball will be brought into contact with the contact ring 24 and, as will be hereinafter more The* vtheir contact rings.

fully described, will electrically connect the ring 24 with the supporting member 20.

By referring particularly to Fig. 4, it will be noted that the uppermost unit ISa has its member 20 formed with a ball supporting surface substantially fiat while walls of the conical surfaces 2| of each of the succeeding units |92), |90, I9d and |9e extend at a progressively increasing angle to the horizontal. Thus when the longitudinal axis of the housing I4 is disposed in the vertical, all of the balls 22 associated with the units Ia, |9b, etc. will be in their lowermost positions, namely, at the apices of their supporting members 20 while, if the housing I4 is tilted at a slight angle, the ball 22 associated with the unit |9a will be moved from its normal position to an abnormal position in Contact with its associated contact ring 24. Further, if the housing I4 is tilted at a greater angle to the vertical, the ball associated with the unit ISI) will move into contact with its contactring, each of the balls being moved from its normal position to its abnormal position upon the tilting of the housing i4 to an angle corresponding to the angle of inclination of the surface 2| to the horizontal or, in other words, each of the balls will move from its normal or central position when the longitudinal axis of the housing I4 is disposed at an angle to the vertical corresponding to the complement of the angle of inclination of the surface 2| to the longitudinal axis of the housing I4. For example, the uppermost unit I`9a may have its conical surface disposed at an angle to the longitudinal axis of the housing I4 of, say, 891/2", while the surface of unit |91) may be disposed at 89, that for units IBc, iSd and |96 may be disposed at lesser angles in increments of 1/ each so as to accurately measure deviations from 1/5 up to at least 3. Then if the well bore deviates by 1 from the true vertical, units |9a and |9b will have been tilted sufficiently to move their associated balls 22 from their central positions and into contact with the respective contact rings 24 while units |90, |9d and I9e will not have been tilted suiliciently to move the balls from their normal positions or into contact with Thus the number of balls which have been moved from normal to abnormal position constitutes a detector denoting that the well bore deviates from the vertical and also constitutes a measuring device which measures the angle of such deviation. While the shifting of the balls in itself constitutes the detecting and measuring portions of the instrument and may be employed as a measure of the angle of deviation of the well bore, we prefer to associate the shifting movement of the balls with suitable translating mechanism which will translate the movement of the balls from one of their positions to the other as intelligence receivable and translatable at the ground surface. For this purpose we prefer to provide sound transmitting apparatus which will be actuated in differing predetermined manners dependent upon the number of balls which have been shifted from their normal to their abnormal positions.

as illustrated particularly in Figs. 4, 6 and '7, this sound transmitting apparatus may comprise a buzzer or vibrator 28. We prefer to employ an electrically actuated vibrator because the same can be constructed of such rugged character as to withstand shocks, vibrations and other conditions which might interfere with or destroy the usefulness of other types 0f vibrating mechanisms. The sound transmitting apparatus illustrated herein includes a suitable core 29 about which is wound an electro-magnetic coil 30 enclosed within a suitable casing 3l in which is mounted, as by a pivot 32, a movable amature 33. The armature 33 is adapted to bear upon a spring contact member 34 and normally press the contact point 35 thereof into engagement with a stationary contact 36 but which, when attracted by the core 29, will allow the contact 35 to move away from the contact 36 and thereby open the circuit to the coil 30 in the manner usually employed in electrical vibrators.

The core 29 has preferably associated therewith a non-magnetic head 31, against which the armature 33 may strike when attracted by the coil 33 so that each time the coil is energized the armature 33 will strike a considerable blow against the head 31, which blow will be transmitted through the metallic parts of the vibrator as a sound vibration. By selecting the distance through which the armature must move and by selecting the mass of the armature as compared with the strength of the coil 39, the vibrator 28 may be caused to actuate at any predetermined frequency to produce a sound vibration of predetermined frequency. The assembly oi the vibrator 28 within the housing i4 is preferably accomplished by forming the casing 3i so that it makes a snug iit within the housing I4 and allowing the casing 3l to abut at its lower end upon a disc 38 of insulating material, which disc may constitute the mounting means for the spring 34 and the contact 36.

Disposed immediately below the disc 38 is an insulating ring 39 having a recess 48 therein cooperating with a recess 40a in an insulating sleeve 4l so as to hold between the recesses 40 and 40a a continuous contact ring 42. Set within and distributed about the insulating sleeve 4l is a plurality of short segmental contact members 43a, 43D, 43e, 43d and 43e, these contact segments being distributed evenly about the inner circumference of the sleeve 4| and disposed a short distance away from the contact ring 42 so that a bridge member 44 when rotated in a horizontal plane will successively connect each of the contact members 43a, etc. with the contact ring 42.

As will be understood, there is a contact segment 43a, etc. for each of the units ISa, i911, etc. Y Y

employed in the instrument so that the contact ring 24 of the unit l9a may be connected by a suitable conductor 45a to the contact segment 43a while the contact rings 24 of each of the units i9b, 19e, 19d, etc. is respectively connected by means of conductors 45D, 45C, etc., with respective contact segments 3313, 43C, etc.

In the form of the device shown in Figs. i and 7, a motor or other rotating device 46 may be employed to successively bridge between the contact segments 43a, etc. and the contact ring 42, this motor being set into a recess 41Ain the in sulating sleeve 4l, the upper end of the motor 46 abutting a shoulder 48 to prevent upward movement thereof relative to the sleeve 4i while a metallic disc 49 having a diameter snugly fitting the interior circumference of the housing i4 may abut the lower end of the motor and hold the motor against downward displacement.

Electric power may be supplied to the motor and to the vibrator 28 from a suitable dry cell battery 50 which may be located within the lower end of the housing i4, held in place therein by the lower cap i6 and having one of its terminals grounded upon the cap I6 while the other of its terminals 5l engages a contact button which is in turn connected by means of a conductor 53 to one terminal 54 of the motor and to one terminal of the vibrator coil 30.

The interconnection between the battery 50, the vibrator 28 and the angle detecting units I 9a, etc., is illustrated diagrammatically in Fig. 'I wherein each of the supporting plates or discs 20 is illustrated as being grounded so that movement of the ball 22 associated with unit |9a will partially complete an electric circuit to the vibrator 28, which circuit will be completed when the contact brush or bridge 44 bridges the contact segment 43a associated with that unit l9a. Assuming that the instrument, disposed with its longitudinal axis parallel to the longitudinal axis of the well bore, is tilted at such angle that the Contact ball 22 associated with unit |9a is engaging its contact ring 24, a circuit will be completed which extends from the battery 50, through a switch 55, conductors 53 and 56 to the coil 30 of the vibrator 28, whence the circuit extends by means of conductor 51 to the contact spring 34, contacts 35 and 36, conductor 58, to contact ring 42. When the brush or bridge 44 bridges Contact segment 43a and ring 42, the circuit will be completed through conductor 45a, the contact ring 24 being associated with unit 19a, ball 22, and metallic disc 20 to ground, the opposite terminal of the battery 50 being grounded as indicated at i6. The vibrator will then be caused to operate to produce sound vibrations of predetermined frequency.

In order to avoid unnecessary depletion of the battery 50, a switch 55 of the character shown and vdescribed in Anschutz-Kaempfe United States Patent No. 1,313,367, may be employed, arranged to maintain its contacts open whenever the instrument is subjected to vibrations such as those encountered in ordinary drilling operations, but which will close its contacts when those vibrations have ceased.

The motor 46, being supplied with current from the battery 50, through switch 55, conductor 53, the iield winding 46a and armature 4Gb of the motor 46 to an auxiliary grounded contact segment 59 comprising an additional segment in the group 43a, 43h, etc. will operate continuously and successively connect the segments 43a, 43h, etc. to ring 42. We prefer to employ the additional contact segment 59 as a monitor to produce one beat in each revolution of the brush 44 to indi- E cate to the listener or operator that the motor 46 is functioning. In other words, upon each rotation of the brush 44, one beat or series of vibrations will be produced whether or not the instrument has been tilted away from the vertical, notifying the operator that the instrument is in operative condition, and then if the instrument has been tilted from the vertical by reason of deviation of the well bore from the true vertical, for example, sufficient only to move the ball 22 of unit |9a, a second beat or series of vibrations will be produced upon each rotation of the brush 44.

Thus if only one oi the balls 22 has been moved to its abnormal position, there will be only two series of vibrations produced upon each revolution of the contact brush 44 while, if others of the balls 22 have been moved to abnormal position, there will be a series of beats or a series of groups of vibrations produced upon each revolution of the brush 44, the number of these beatsdepending upon the number oi balls. which have been moved. Thus by listening to the sound produced there will be received an indication of the angle of inclination of the well bore, the measure of which angle depends upon the number of beats per cycle of rotation of the brush M.

For example, if three beats followed by a long pause is heard, this will be an indication that units I9a. and I9?) have been tilted to such angle that the balls 22 associated therewith are in abnormal position and that the angle of inclination is 1 from the vertical since only at this angle will both of the balls 22 associated with units I9a and ISb be in abnormal position while the balls 22 of the remaining units will be in their normal central positions. Again, if four beats followed by a pause is heard, ity will be an indication that the angle of inclination of the well bore from the vertical is equal to the angle selected for the surface of unit ISC.

These vibrations may be transmitted to the ground surface as electrical vibrations or sound vibrations as desired though, in order to avoid the necessity of providing conductors extending down through the well bore, we prefer that the sound vibrations be transmitted upwardly through the metallic parts of the drill string, casing or other metal which extends into the well bore.

A convenient way in which to receive these sound vibrations and to segregate the predetermined frequency vibration produced by the vibrator 28 from any other extraneous vibrations. is illustrated in Fig. 6 wherein a microphone 60 is illustrated as being placed against some metallic part of the drill string or its supporting mechanism, preferably against either the gooseneck 8i for the mud hose or some other part of the metallic portions of the well drilling structure which will not be rotated during the normal drilling operations. The microphone 60 will receive the sound Vibrations emanating from the vibrator 2B and will'pass these vibrations as electrical vibrations to a filter 62 by means of conductors 63.

The filter 62 may be of any character well knownV in the radio art which will lter out all vibrations other than those of a, predetermined frequency band, allowing only the electrical vibrations of the desired frequencies to pass to a suitable ampliiier 64 at which the vibrations will be amplified at least to an extent capable of permitting them to be detected by earphones or other receiving apparatus B5. Thus by listening at the earphones or loud speaker 55, the operator will be able to determine instantly whether or not the well hole deviates from the vertical and to what extent. If desired, an electrical recording apparatus 66 of any of the well known characters may be employed to produce a permanent record 61 of the impulses or beats received from our instrument below the ground surface.

It will be observed from an inspection oi Figs. 4, 5, 6 and 'l that all or" the parte o F. the instrument contained within the housing :i may be made oi relatively rugged character and that there are no delicate bearings, pendulums or other devices which are incapable of withstanding great shocks, great vibration and considerable abuse. The balls 22 may be made of hardened steel and the disc supports 2t be made ol hardened steel. The diameter of the casing l may be relatively' small, as small as /g inch, so that the total distance through which any of the balls 22 move between their normal and abnormal positions may oe so small as to prevent the building up or' any appreciable amount ci kinetic energy and thus the strength of all of the parts relative to the mass of all of the parts may be maintained at a high value. Again it will be noted that there is nothing in lthe apparatus thus far described which cannot withstand falls, shocks or other abuse so long as such abuse is insui'iicient to completely crush the shell of the housing I4.

By reason of the rugged character o1` the instrument thus far described, it will be apparent that one important advantage is that it may be permanently associated with the drilling tools and allowed to remain in the hole during the normal drilling operations, requiring only that the drilling operations be paused long enough i'or the balls 22 in the instrument to come to rest in order to produce the desired indications of whether or not the hole has deviated from the vertical and to what extent.

For example, as illustrated in Figs. 1, 2 and 3 herein, the housing I4 may be detachably fixed within a recess 68 in the drilling sub 3 normally employed immediately above the drill bit 2.

By reason of the fact that our instrument may be made of relatively small diameter, the entire housing I4 may be contained within a relatively small diameter and shallow recess in the side wall of the sub 3 out of the way of mud fluid which is passing down through the usual circulation opening 69 in the sub 3 and equally out of the Way of the mud fluid passing up about the exterior of the drill bit and sub. For example, as shown in Figs. 2 and 3, a shallow recess t8 may be cut into the side wall oi the sub 3 just sunlciently deep to permit the complete enclosure of the housing I4 within the circle described by the exterior circumference or the sub 3 and the instrument may be maintained within this recess by means of a suitable cap lu removably attached to the sub 3 as by bolts 1|. As will be understood by those skilled in the art, the sub 3 is relatively long so that ample space is provided thereon for a relatively long housing I4 but the cross sectional area ol' the sub 3 is limited by the diameter of the hole and also by the diameter of the wash opening 68. 'lhus our instrument, being capable of construction of relatively small diameter and of sufficient length to accommodate all of the apparatus contained within the housing I4, is readily adapted to be detachably fixed to the bit, sub or other drilling tool. It will be noted that the disposition of the recess 68 and the mounting of the housing I4 therein is such that the longitudinal axis of the housing I4 is always maintained parallel to the longitudinal axis of the bit, sub or drill string so that if the axis of the bore deviates from the vertical, the longitudinal axis of the bit, sub or lower portion of the drill string will also deviate from the vertical in the same manner and to the same degree and thus will dispose the longitudinal axis of the housing I4 at the same angle to the vertical as the axis of the well bore deviates from the vertical. I

It will also be noted that by reason of the rugged character of all of the parts of our instrument, this instrument may be either dropped down from the ground surface through the wash opening in the drill string and allowed to fall therethrough freely by gravity without danger of breakage or disability and avoiding the necessity of providing cushioning devices or mechanism heretofore required by all other instruments of this character. In other words, the instrument may be dropped freely through the wash opening of the drill pipe and as it falls therethrough the displacement of the drilling fluid will tend to retard the gravity fall of the instrument while when the instrument arrives at the lower end of the hole it will come to rest upon the drill bit and, even though it should be brought to rest with considerable rapidity, the shock thereof will be well below any possibility of breakage of the instrument.

On the other hand, it may be desired. to ewer the instrument from the ground surface upon a cable or wire as is illustrated particularly in Fig. 16, the housing i4 having upon its upper end a suitable coupling l2 to which wire, cord or cable 13 may connect and the housing i4 preferably having an external di meter somewhat smaller than the diameter 1 wash opening 69 in the drill string sub "nd bit sc that by providing spring nngers 'it distributed about the housing lli, the housing l will be maintained with its longitudinal axis aligned with the longitudinal axis of that part of the drill string through which it s passing or at which it has come to rest.

While we prefer to employ umts i90., i927, etc., having conical depressed surfaces 2i, it will be apparent to those skilled in the art that other types or configurations or" surfaces may he em ployed; for example, a concave surface. The curvature of this surface in one of the units may be described by a given diameter so that it will be necessary to tilt the instrument to at least an angle or 1 from the vertical in order for the ball to move from a central or normal position thereon while the curvature of the surfaces oi the other units may be ci progressively lesser diameter, requiring the tilting of the instrument to a greater angle before the balls `:vill move to their abnormal or contacting positions.

However, by employing the conical depressed surface, it will be apparent that the balls will remain in their central or normal positions un til the instrument has been tipped to an angle complementary to the angle of inclination of the surface relative to the vertical before the bali will start to move and then when the instru" ment has been tipped or tilted te this position the balls will move from 'their central or normal position to their abnormal or contacting position. In other words, by employing a surface of this character the balls will move only when the in-l strument is tilted to an angle equal to the com@ plement of the angle of inclination of the suris provided near its center with a depression. i5 e associated with detecting unit. In Fig. we have illustrated the surface of the supporting disc as cmribining the de-1 we il 'with the depression thus pe :sitting all ci the units to be com struct/ed cir surfaces 2l with sare conical depression permitting the variation oi the depth ci? the depression "5 to control cr determine the angle which. insti-inherit must be tilted before the ball 22 will move from its central or normal position.

In Figs. 10 and l1 we have illustrated a slightly modiiied form of surface which may be used, in which the supporting disc 20c`is provided with a pair of transversely extending slots of sufficient width to allow the ball to roll along any of the slots from the lowermost point I6 (disposed near the central axis of the disc 20c) In this case the ball 22 is not free to roll in all directions but may roll in any one of four directions from the center 16 toward the contact ring 24. It will be apparent that if desired a cylindrical roller or other shape of rolling member may be substituted for the ball provided only that the rolling member must be capable of freely rolling on the surface 2i by gravity.

in some instances it may be desirable, once the ball 22 has been moved from its central or normal position, that it should be maintained in its abnormal position until the instrument has been withdrawn from the well bore, in which case the supporting disc 20d may be employed as shown in Fig. l2 wherein the surface 2id has av depression 'il near its center and also is depressed near the outer circumference as indicated at 18. The ball, once moved from the central position. will remain in its abnormal position, indicated in dotted lines in Fig. l2.

Also it may be desirable in some instances to substitute a closed circuit electrical system for the open circuit electrical system shown in Fig. 7. Such arrangement is shown in Figs. l2 and i3 herein wherein each of the supporting discs 20d is provided at its center with a central bore 'I9 into which may be pressed a bushing of insulating material. A contact pin 8l may project upwardly through the bushing 80 and be normally urged upwardly by means of a spring 82, insuiiicient in strength, however, to overcome the weight of the ball 22 when the ball is in its normal or central position. Thus whenever the ball 22 is in normal position the ball will contact the surface 2id and the contact pin BI, closing the electrical circuit at this point. Referring now to Fig. 13, it will be observed that the electrical circuit contre-lied by the balls 22 constitutes a closed circuit extending from the battery 5U through switch 55 and conductor 83, from which branch circuits extend to each of the units |911, lh, iSc, etc. One of these circuits extends by way of conductor 84, the coil of a relay B5, conductor 86, to the contact pin 8| associated with the disc 20d on unit i911; whence the circuit extends, through the ball 22 and the disc 20d to ground at 8l. The relay 85, being normally energized whenever the bail 22 is in central or normal position, will hold its contacts open, preventinry the establishment of a circuit to the vibrator 28 until the ball has been moved from its normal to its abnormal position;

The circuit thus for described may` be subspt ted for the electrical connections shown'in "ie units iga, iSb, i90, etc. and i3d, 43h, 43e, etc. merely ntacts of the relays asso- 5 the units Ilia, No, i90, etc., the respective contact segments 43a, 43h,

En Fig. 13, however, we have illustrated a sub- 'itute electrical system, permitting the motor dispensed with and illustrating the manmay be readily acconmlisl` trol relay for the timing7 asoasco other segment and brush contacts, such as 42, 43a, and 44 shown in Fig. 7.

In Fig. 13 we have illustrated such substitute electrical system as being applied to three detector units |9a, |912, |9c, etc. though it will be understood that as many more units may be employed as is desired in a completed instrument. Associated with each of the units |911, |91), E9e, etc. is a relay which may be constructed of'such rugged character as to insure its successful operation under the most trying conditions of abuse. One of these relays A is associated with unit lila, a second relay B is associated with unit |911, and a third relay C is associated with unit |9c so that by connecting the relays A, B, C to operate in sequential relation with respect to each other in a predetermined time cycle, these relays will during each cycle connect its associated unit with the vibrator 28. This may be readily accomplished as is illustrated in Fig. 13 by connecting the coil of the relay A to be energized a predetermined time period after the relay C has been energized and connecting the coil of the relay B to be energized at a predetermined time after relay A has been energized and so on throughout the entire cycle, each lrelay when actuated serving to prepare the circuit for the next relay and also serving to deenergize the preceding relay in the cycle.

For example, the coil of the relay A may be connected in an electrical circuit which extends from the battery 50 through conductors 83, 88 and 89 to the lowermost contacts of relay B (arranged to be closed 'whenever relay B is deenergized and arranged to be opened whenever relay B is energized). Thence the circuit extends by way of conductor 90 to the coil of relay A, whence the circuit extends by way of conductor 9| to the contacts b on relay C, conductors 92 and 93 to normally close contacts b on a timing relay T and thence by Way of conductor 94 to ground at 95.

Thus whenever relay C is energized, as |will be described hereinafter, its contacts b will prepare a circuit for the coil of relay A, which circuit will be completed as soon as timing relay T closes its normally closed contacts b.

In order to prevent the energization of rela A until a predetermined time period after relay C has been actuatechthe timing relay T is arranged with a dash pot or other retarding device to momentarily close its normally closed Icontacts after deenergization of the -coil of said relay in any manner well known. in the art. This time delay may be selected as of any desired value though we prefer that the same be only a matter of a fraction of a second, sufficient only to ermit the distinction between successive beats pr duced by the vibrator 28x The relay T is therefore arranged to be actuated Vrepeatedly at regular intervals, which d by providing a con- .ay T indicated herein as-relay TR. Relay has its coil connected in a circuit extending from the battery 50, through conductor 83, conductor 96, normally closed contacts c ci relay T, conductor 9i', coil. o relay TR and conductors Q8 and 99 to ground at 95. Relay TR, will thereiore ne energized whenever relay T has been deenergized and the time relay imposed upon relay T has expired. Relay TR when energized closes its contacts to complete an energizing circuit for relay T, which circuit extends from the battery 50, through conductor 83, conductor itil, the coil oi' relay T, conductor |0|, the contacts of relay TR and conductors |02 and 99, to ground at 95. Relay TR. closing its contacts energizes relay T; relay T when energized opens the circuit for relay TR, thus deenergizing relay T. By properly selecting the time delays in the operation of the relays T and TR, relay T may be arranged to close contacts b momentarily a given number of times in a predetermined time cycle.`

Thus relay C, having prepared the circuit for relay A, will cause energization of relay A upon the next closing of contact b on the time relay T. Relay A when energized closes its contacts a to provide a self-holding circuit for relay A to maintain this relay energized until the holding circuit is opened. This circuit extends from the battery 50, through conductors 83, 88, 89, the normally closed contacts on relay B, conductor 90, to the coil of relay A, vas hereinbefore described, whence the circuit extends by way of conductor |03 to the contact a on relay A, conductors |04 and |05, to ground at |06.

Relay Awhen energized also closes its contacts c which couples unit |9a to the vibrator 28, this circuit extending from the battery 50, through conductors 83 and |01, vibrator 28, conductor |08, contacts c on relay T, conductor |09, contact c on relay A, conductor ||0 to the contacts of relay 85, which contacts will be open if the ball 22 of unit |9a is in its normal position but will be closed if this ball is in abnormal position. If the ball is in abnormal position, the circuit is completed through the contacts of relay 85 to ground at and as soon as relay T again picks up the vibrator 28 will be actuated to give one beat or series of vibrations.

Relay A when actuated prepares a circuit for relay B similar to the circuit which was prepared for relay A by relay C, this circuit being cornpletedupon the next operation of timing relay T. As soon as timing relay T again operates to close its contacts b, relay B will pick up and inso doing will open its normally closed contacts d, interrupting the previously completed self-holding circuit for the relay A, allowing relay A to drop out and remain deenergized until relay C has again been actuated.

Relay B upon closing also completes a selfholding circuit similar to that described for relay A and also closes at its contacts c a circuit which connects or couples the unit |9b with the vibrator 28, causing the vibrator to produce a series of vibrations or a beat if the ball 22 associated with unit |92) is in its abnormal position.

Likewise relay B when energized partially compietes a circuit for relay C, which circuit can only be completed, however, upon the subsequent actuation of relay T. Relay C, like relay B, has its normally closed contacts c in the self-holding circuit for relay B so that as soon as relay C is energized, relay B is cut out. Relay C has its contacts c connected with the unit so as to couple this unit with the vibrator 28 and, if the ball 22 associated therewith is in abnormal position, a third series of vibrations or beats will be produced by the vibrator 28.

It follows therefore that once relays A, B and C have been set into actuation by the energizing of any one of these relays, they will continue to operate in sequence A, B, C, A, B, C, until the circuit is opened at switch 55, producing the same result of sequentially connecting the several inclination detecting units |9a, |917, etc. with the vibrator 28 so that the signal produced will be a series of vibrations or beats, the number of which will depend upon the number of detector units iSa, i917, etc., which have had their rollers, balls or other movable devices moved to abnormal position by reason of the inclination of the well bore.

In order to start the sequence of operations relays A, B and C, we prefer to provide on the switch 55 additional contacts indicated diagrammatically as switch H2, which may be arranged upon the structure of switch 55 so as to be momentarily closed when switch 55 is closed but to immediately thereafter open.

The switch ||2 is illustrated as being connected in a circuit shunting Contact a or" relay A so that an initial energizing in pulse is given to relay A and then, as soon as relay A has once been operated, the sequential operation of relays A, B and C will follow.

The various detector units isa, |92), etc. may be connected to the segmental contacts 43a, 43o, etc. in the form of the device shown in Fig. 4 or with the sequential units A, B, C, in the form of the device shown in Fig. 13 by suitable conductors which may extend through the slots ||5 in the supporting discs and in the insulation rings and 26 (see Fig. 4), these slots being aligned with each other in such manner as to form a conduit through which the conductors may pass.

ISimilarly, the battery 50 may be interconnected with the motor 46 and the vibrator 28 .by means of a conductor 53 which extends upwardly through conduit slots H6 in the discs 20 and insulation rings 25 and 26. Likewise in the form of the device shown in Fig. 13, conductor 53 which leads upwardly to supply current to the various relays, may pass through the slot I |6 in the same marmer as described for the motor and Vibrator circuit conductor. Y

However, in order to adapt our instrument to ready adjustment for any desired number of detector units, we may employ the arrangement shown in Figs. 14 and l5 wherein each of the detector units Z911: is illustrated as comprising a relatively deep ring of insulation material formed with an annular interior recess H8 into which the supporting disc 20 may seat against a radial flange H9, with a tongue 201,f extending to the exterior surface oi ring ill to make grounded contact with the housing |l. A second ring of insulation material |20 is secured directly upon the ring lil having a recess |22 oooperating with a recess |23 in ring lil to act as a seat for the contact ring 24x. The rings ill and |2 may be held together by means of rivets |24 which are preferably constructed as shown in Fig. 15, oi an elongated tubular portion extending through the rings |28 and lll and having their lower ends |25 peened out to forni a dared entrance opening thereat and to rivet these tubular members in place. The upper ends of rivets E215? may be provided with enlarged shoulders i, from which pins |21 extendppward'y, of such diameter as to be readily received within the openings at thelower ends of tubular rivets associated with another one of the detector units |92.

As is illustrated in Figs. i4 and i5, eight of these rivets may be distributed in evenlyY spaced relation about the circle described by units |932, all of the rivets |24 except one extending entirely through the unit to receive pins from another unit disposed below the rst unit. One of these rivets |241: is short, extending only through the ring |21), and is connected as by as indicated at |28. Immediately below the short rivet |20 the ring is provided with a short bore or opening .529 capable of receiving the pin |21 of a rivet on the next lowermost unit in the assembly.

By employing the construction shown in Figsf 14 and 15, it will be apparent that the rivets constitute plug and jack connections by which six units may be assembled one upon the other, one of the rivets |24 of the lowermost unit acting asa conductor for the power supply line 53 while its short rivet |24 plugs into a long rivet in the unit assembled immediately above it. A third unit may be plugged in upon the second unit. a fourth unit upon the third, and so on, care being taken only to rotate each of the uppermost units 1/8 of a revolution before plugging in so as to plug the short rivet of each unit into a long rivet into the next uppermost unit, without interferring with or interrupting the circuits extending upwardly from all of the lower units.

It will be observed therefore that we have provided a measuring device for detecting and measuring the angle of inclination of a well bore which may be constructed of such rugged material and which has all of its parts m'ade of such rugged character that the instrument may be handled with a small amount of care and may be subjected to considerable abuse without danger of injury to any of the parts. It will also be noted that our unit is of such small diameter that it may be readily fixed to any of the well known drilling tools or other tools which are sent down through the well bore so that by the mere stopping Aof the rotary drilling for a few seconds, giving the switch 55 time to close its contacts, an indication of the condition of the Well bore may be made at any time. By reason of this construction, allowing a small diameter for the instrument, it may be either dropped from the surface when an indication is desired or it may be lowered upon a cable or wire when an indication is desired, the instrument passing down through the usual mud fluid bore in the drilling apparatus and, by reason of its rugged character, the instrument may be dropped rapidly and allowed to strike the bottom of the well bore or the tools at the bottom of the well bore without injury even though no cushioning apparatus is employed.

It will also be noted that by employing our instrument the smallest deviation of the Well bore from the true vertical will be immediately transmitted to the surface of the well where it may be detected and translated, giving the operator sufficient information to allow him to straighten the well bore and prevent further deviation thereof.

While we have shown and described the preferred embodiment of our invention, we do not desire to be limited to any of the details illustrated or described herein except as defined in appended claims.

l. lin a. device for' measuring the inclination of a bore, i. dy member insertable in said well bore and adapted to dispose the longitudinal axis of said body member parallel with the axis of said bore; a plurality of movable means in said body member each movable from a normal position to an. abnormal position upon inclinasoldering or otherwise to the contact ring 24x, '2'5 tion oi' said axis of said body member from the vertical at an angle different from that of the others of said means; an indicating device; a plurality of electric circuits, one for each of said movable means, each of said circuits including means for energizing that circuit actuated by movement of the associated movable means to an abnormal position; and means for consecutively connecting said indicating device to said circuits for actuation by each of said energized circuits whereby the number of actuations of said in'dicating device indicates the angle of inclination of the said housing from the vertical. 2. In a device for measuring the inclination of a well bore, a body member insertable in said well bore and adapted to disposeits longitudinal axis of said body member parallel with the axis of said bore; a plurality of movable means in said body member each movable from a normal position to an abnormal position upon inclination of said axis of said body member from the vertical at an angle different from that of the others e ,of said means; an indicating device; a plurality A of electric circuits, one for each of said movable means, each of said circuits including means for energizing that circuit actuated by movement of the associated movable means to an abnormal position; and means for repeatedly connecting said indicating device to said electric circuits consecutively in a predetermined time cycle, whereby the number of actuations of said indieating device in said cycle indicates the angle of the inclination of said housing from the vertical.

3. In a device for measuring the inclination of a well bore, a body member insertable in said well bore and adapted to dispose its longitudinal laxis parallel with the axis of said bore, means movable from a normal position when said axis is vertical to an abnormal position when said axis is inclined to the vertical, mechanism actuated by movement of said means from said normal position for producing a signal of predetermined frequency, and translating means for receiving and translating said signal and a means associated therewith forV preventing response of said translating means to any frequency other than said predetermined frequency.

4. In a device for measuring the inclination of a Well bore, a body member insertable in said Well bore and adapted to dispose its longitudinal axis parallel with the axis of said bore, means movable from a normal position when said axis isverticali to an abnormal position when said axis is inclined to the vertical, mechanism actuated by movement of said means from said nor? mal position for producing a sound vibration of predetermined frequency, sound responsive means for receiving and translating said vibrations and having means associated therewith for preventing response of said sound responsive means to any frequency other than said pre determined frequency.

5. In a device for measuring the inclination of a Well bore, a body member insertablein said Well bore and adapted to dispose its longitudinal axis parallel with the axis of said bore, means movable from a normal position when said axis is vertical to an abnormal position when said axis is inclined to the vertical, mechanism actu-z ated by movement of said means from said normal position for producing a sound vibration of predetermined frequency, sound responsive means for receiving and translating said vibrations and having filter means for filtering out all frequencies other than said predetermined frequency.

6. In a device for measuring the inclination of a well bore, a body member insertable in said well bore and adapted to dispose its longitudinal axis parallel with the axis of said bore, a plurality of movable means in said body member. each movable from a normal position to an abnormal position upon the inclination to the vertical oi said axis of said body member at an angle diilerient freni the angles at which the others of said means are movable, indicating means associatedwith said movable means for indicating the disposition of any of said movable means 'from normal position, and means for consecutively coupling said movable means to said indicating means whereby the number of said movable means disposed in abnormal position may be indicated.

. 7. In a device for measuring the inclination of a well bore, a body member insertable in said well bore and adapted to dispose its longitudinal axis parallel with the axis of said bore, a plurality of movable means in said body member, each mov-J able from a normal position to an abnormal position upon the inclinationto the vertical of said axis of said body member at an angle diiierent from the angles at which the others of said means are movable, signal means for producing a signal associated with said movable means to be actuated by any of said movable means disposed away from its normal position, and means for consecu-n tively coupling said movable means to said signal means to produce a series of signals the number of which indicates the angle of inclination of sai bore to the vertical.

8. In a device for measuring the inclination of a well bore, a body member insertable in said Well bore and adapted to dispose its longitudinal axis parallel with the axis of said bore, a plurality of movable means in said body member, each mov-n able frem a normal position to an abnormal position upon the inclination to the vertical of said axis of' said body member at an angle different from the angles at which the others of said means are movable, indicating means associated with said movable means and actuated in response to the disposition of any of said movable means away from its normal position, an electrical circuit for actuating said indicating means including a branch circuit for each of said movable means, and means for consecutively coupling said branch circuits to said indicating means whereby said indicating means will produce a series of indications the number of which corresponds to the number of said movable means disposed in abnormal position.

9. In a device for measuring the inclination of a well bore, the combination of a self-contained instrument insertable in the well bore including, a plurality of movable means each movable from a normal position to an abnormal position upon inclination to the vertical of the axis of said instrument at an angle different from the angles at which the others of said means are movable, signal producing means associated with each of said movable means and actuated thereby when said movable means is in abnormal position; and

- means at the ground surface for receiving the signals produced by said signal producing means for determining which of said movable means has been moved to abnormal position to thereby indicate the angle of inclination of said instrument from the vertical.

l0. In a device for measuring the inclination of a well bore, the combination of a self-contained instrument insertable in the Well bore including, a piurality of movable means each movable from a normal position to an abnormal position upon inclination to the vertical of the of said in strument at an angle different from the angles at which the others oi said means are movable, signal producing means associated with each of said movable means and actuated thereby when said movable means is in abnormal position, and means independent of said movable means for actuating said signal producing means; and means at the ground surface for receiving the signals produced by said movable means and by said independent means for determining operativeness oi the instrument and for determining which oi said movable means has been moved to abnormal position.

1l. In a device for measuring the inclination oi a well bore, a body member insertable in said well bore and adapted to dispose the longitudinal axis of said body member parallel with the axis of said bore; a plurality of movable means in said body member each movable from a normal position to an abnormal position upon inclination of said axis of said body member from the vertical at an angle different from that of the others oi said means; an indicating device, a plurality of elecm tric circuits, one for each of said movable means, each oi said circuits including means for energizing that circuit actuated by movement of the associated movable means to an abnormal position; an additional circuit including means normally energizing the same; and means for consecutively connecting said indicating device to said circuits for actuation by each cf said energized circuits whereby the number of actuations of said indicating device indicates operativeness of the instrument and the angle of inclination et the said housing from the vertical.

12. In a self-contained unit for determining the inclination oi a bore hole from the vertical, a casing containing therein the following instrumentalities; a source of electrical energy, a plu- -rality of movable members movable from a non mal position to an abnormal position upon in olination of said casing from the vertical, each member being movable upon inclination of the es: iron: vertical at an angle diiicrent from the angles at which the other members are movable and each member having means for completing a partial circuit including said source, an electrically operated sound generating device and means for repeatedly sequentially vcompleting through the generating device the partial circuits capable of being prepared by the movable members, whereby the number of partial circuits prepared by said members for a. given inclination oi the casing and completed by the sequence means during each repetition is manifested by the number of operations of the generating device for each repetition.

13. In an oil well instrument, means actuatable to measure conditions in a well bore, signalling means operable in response to actuation of said measuring means to transmit to the ground surface signals the number of which is representative of the measurements made therebyy actuating means operable to actuate said measuring means, and means responsive to operation of said actuating means for operating said signalling means independently of the actuation of said measuring means to thereby produce another signal indicating the operative condition of said signalling means.

14. In an oil well instrument, means actuatable to measure conditions in a well bore, signalling means operable in response to actuation oi' said measuring means to transmit to the ground surface sound signals the number of which is representative of the condition measured by said measuring means, actuating means operable to actuate said measuring means, and means responsive to operation of said actuating means for operating said signalling means independently of the actuation of said measuring means to thereby produce another sound signal indicating the operative condition oi said signalling means.

ELU/[ETT M. IRWIN. RAY M. CHENOWETH. RICHARD H. DUVAL. 

